How Do I Change Fuel Pump On 1991 Chevy. 1500 Truck?

In order to change the fuel pump on a 1991 Chevy 1500 truck, you will need to remove the fuel tank because the pump is located inside it.

The first thing that you need to do is to relieve the pressure in the fuel tank by loosening the fuel filler cap. You will then need to disconnect the cable that leads to the negative battery cable (use a socket wrench for this).

Once this is done, raise the rear end of your truck onto jack stands and drain the fuel tank into a suitable container (obviously, this is a job that is made easier if you do not have a full tank!) You can then remove the fuel tank.

You will find the fuel pump assembly on top of the fuel tank. Turn the locking ring for the fuel pump assembly counter-clockwise by using a drift punch and a hammer. Pull the fuel pump assembly away from the tank, and disconnect the pump from the rest of the assembly.

Find the bottom support of the fuel pump, and pull it away into the attaching hose, and out of the connector. Make sure that you do not damage the fuel strainer and insulator while you are doing this.

Remove the O-ring and install a new one on the fuel pump assembly. Attach the new fuel pump to the hose without twisting the fuel strainer. Put the fuel pump assembly into the fuel tank and turn the locking ring for the pump until it is tight.

Once this is all completed, you can put the fuel tank back in and lower your truck using the jack stands. Re-connect the battery, refill the tank, tighten the fuel filler cap, and you’re all done.

I would slide the box back about two or three feet. Then you can see the top of the gas tank and remove the fuel pump easily. The box if I remember has eight (8) bolts holding it in place. An impact wrench would help. After the bolts are removed you need to undo the wiring harness going to your tailights. You need to get a couple of friends and something like a wooden horse to support the box when you slide it back. If you've ever had to drop a gas tank, which is the other method you'll agree that sliding the box back is much easier.
Jaker

Releive the pressure from the fuel system, drain the fuel tank, disconnect the battery, jack the truck and put on jack stands, disconnect the hoses from the filler tube, disconnect the fuel filter to ensure the pressure is released the the tank is drained, put a transmission jack under the fuel tank, remove the front and rear bans thats holding the tank in place, lower the tank enough to diconnect the fuel lines and wiring harness, slowly lower tank and look for any other obstructions, slid tank from under truck, with a brass punch tap the holding ring counter clock wise and remove, pull the pump out carefully and replace pump all wiring and seals, do reverse to put back together.

You must either drop the tank after you siphon as much of the gas out as you can or get several strong friends to help lift the bed off after you unbolt it. Either way works, dropping the tank entails unhooking a lot of wires and hoses before unstrapping it from the frame. Removing the bed gives topside access to the fuel pump with out dropping the tank. Get the cheapie manual from Autozone, it has all the info and directions you need.

That's really a tough problem and it is not possible that I can teach you all the steps for doing that. But I'm giving you a very good link and by going through that link you'd learn how to change the fuel pump. The link is given below
click here

Drop bed access to pump remove and install

Would it be easier to remove the bolts from the bed and slide the bed aside and do it from the top of the tank.. Especially if it has lots of gasoline in it.. Appears easier and quicker..
Opinions welcome.
Rt